The present invention relates to apparatus for reducing the risk of sudden infant death syndrome, asphyxiation, apnea syndrome and hypoventilation through the use of improved sleeping pads, bedding and bumper pads within a crib or the like to improve the respiratory efficiency and environmental temperature of an infant.
Sudden infant death syndrome (SIDS) is the leading cause of postneonatal infant death in the United States. About 7,000 deaths occur each year from SIDS. In addition, many infants die each year of asphyxiation while in a crib.
SIDS is defined as the sudden death of an infant under 1 year of age that remains unexplained after a thorough case investigation, including performance of a complete autopsy, examination of the death scene, and review of the clinical history.
Prone sleeping is associated with spontaneous face-down sleeping in infants. The face-down position is associated with rebreathing expired gases, including carbon dioxide, and increased carbon dioxide lung pressure in normal infants. In some cases the amount of rebreathed carbon dioxide is sufficient to cause death in normal infants. B. A. Chiding and B. T. Thach, Impaired ventilation in infants sleeping facedown: Potential significance for sudden infant death syndrome, J. Pediatrics, Vol. 123, 686 (1993); J. S. Kemp and B. T. Thach, Sudden Death in Infants Sleeping on Polystyrene-Filled Cushions, New England Journal of Medicine, Vol. 324,1858 (1991). In that case the cause of death is asphyxiation, not SIDS. However in SIDS""s cases the rebreathing of carbon dioxide, short of asphyxiation, may be a contributing cause of the death of the infant.
A brain defect has been discovered that may be the cause of some cases of SIDS. H. C. Kinney, J. J. Filiano, L. A. Sleeper, F. Mandell, M. Valdes-Dapena, W. F. White, Decrease Muscarinic Receptor Binding in the Arcuate Nucleus in Sudden Infant Death Syndrome, Science, Vol. 269, 1446 (1995). That study suggests that a normal infant""s nervous system detects progressive hypercarbia (excessive carbon dioxide in the blood) and asphyxia (stoppage of breathing) and responds by arousal and a series of protective reflexes to ensure airway patency whereas the SIDS infant having the defect does not perform these protective reflexes. The present invention compensates for this brain defect by continuously removing expired carbon dioxide from the crib and providing fresh room air to stimulate breathing. This compensation occurs for all facial positions including face-down.
Other studies have shown an association between excessive clothing and bedding and an increased rate of SIDS. W. G. Guntheroth, P. S. Spiers, Sleeping Prone and the Risk of Sudden Infant Death Syndrome, JAMA, Vol. 267, No. 17 (1992). It is believed that excessive clothing and bedding produce hyperthermia (overheating) within the infant.
The American Academy of Pediatrics recommends that an infant be placed on its back (supine position) when sleeping because the incidence of SIDS is greatly reduced as compared to the prone position. American Academy of Pediatrics, Positioning and SIDS, Pediatrics, Vol. 89, No. 6 (1992). However, when the infant is three to four months old it is capable of rolling over to the prone position. The supine position is considered particularly unsafe for infants suffering from respiratory distress or excessive regurgitation after feeding.
Pediatricians recommend use of a firm mattress and the avoidance of unduly soft bedding. It is believed that such measures will prevent the infant from sinking into the mattress and bedding and thereby avoid restricting the availability of ventilation and oxygen.
Periodic breathing is a normal phenomenon in which an infant""s breathing is interrupted by recurrent apneas (absences of breathing). It has been shown that an increase in ambient oxygen concentration reduces the incidence of apnea in infants. J. Katwinkel, Neonatal/Apnea: Pathogenesis and Therapy, J. Pediatricas, Vol. 90, 342 (1977); T. Hoppenb-Brouwers, J. E. Hodgman, R. M. Harper et al., Polygraphic studies of normal infants during the first six months of life: I.V. Incidence of Apnea and Periodic Breathing, Pediatrics, Vol. 60, No. 418 (1977); N. N. Finer, K. J. Barrington, B. Hayes, Prolonged Periodic Breathing: Significance in Sleep Studies, Pediatrics, Vol. 89, No. 3 (1992). Those sleeping infants who are not aroused by increases in oxygen level (hypoxic arousal) were determined to have a greater risk of SIDS. Perhaps excessive rebreathing of carbon dioxide has an anesthetic effect on the sleeping infant which can be overcome in most cases by increasing the ambient oxygen level.
While no specific cure of SIDS is known, the above studies as well as other medical research suggests that neurological disorders, sleeping in the prone position, rebreathing expired carbon dioxide and overheating may each be a contributing cause.
Since almost all cases of SIDS and asphyxiation occur in cribs, it is reasonable to investigate the characteristics of the crib system consisting of the infant, clothing, mattress, bedding and bumper pads in order to determine whether some of these system components, excluding the infant, are contributing environmental causes of SIDS and asphyxiation.
The U.S. Consumer Product Safety Commission (CPSC) has studied rebreathing of carbon dioxide using rabbits as well as a doll in combination with a mechanical lung. N. J. Scheers, Infant Suffocation Project, Final Report, U.S. Consumer Product Safety Commission, January, 1995. In those studies the amount of rebreathing of carbon dioxide was measured for a variety of infant bedding items. The test included death scene re-creations. It was found that expired carbon dioxide enters infant bedding and provides a xe2x80x9cpoolxe2x80x9d of carbon dioxide for rebreathing. The results showed that rebreathing carbon dioxide trapped in soft bedding products may have contributed to the deaths of the estimated 30 percent of the infants found in potentially suffocating circumstances. In addition, the CPSC recommended against use of decorator pillows or the like in the crib environment to further lessen the likelihood of suffocation.
Concerning the xe2x80x9cpoolxe2x80x9d of carbon dioxide found by the U.S. Consumer Product Safety commission, since carbon dioxide is fifty percent heavier than air, the exhaled carbon dioxide moves downward but its movement is blocked by the mattress, which results in the formation of the xe2x80x9cpoolxe2x80x9d of carbon dioxide at the top of the mattress and in bedding. If the conventional mattress is replaced by a foam pad with holes therethrough, as in the present invention, the downward movement of carbon dioxide would no longer be blocked so that carbon dioxide would move downward through the holes and out of the crib, so that the xe2x80x9cpoolxe2x80x9d of carbon dioxide would be reduced or eliminated, and rebreathing of carbon dioxide would be reduced or eliminated.
Prior art devices for reducing the likelihood of SIDS usually focus on an infant""s respiration and attempt to provide oxygen to the infant while removing expired carbon dioxide efficiently. In other words, they attempt to increase ventilation within the crib. It is known that conventional bedding is minimally gas permeable and causes xe2x80x9cpoolingxe2x80x9d of potentially dangerous expired carbon dioxide within the bedding for rebreathing.
One such device is disclosed in U.S. Pat. No. 5,389,037 to Hale. The Hale apparatus includes an air plenum assembly, including an electric blower, attached to the crib to mechanically direct a flow of air toward the infant. Still another device is disclosed in U.S. Pat. No. 5,317,767 to Hargest et al. In that device, air is directly introduced in to the crib environment through an air permeable mattress upon which the infant rests. Yet another device is disclosed in U.S. Pat. No. 5,305,483 to Watkins which describes a mattress pad whereby the pillow portion is provided with a pump and ventilation means to constantly pump air through numerous air pockets supplied within the pad.
Each of these devices is complex, requires an electric power source, is noisy and obtrusive and may be uncomfortable for the infant. Further, the Hargest and Watkins devices require supplemental supports positioned underneath their pads since the air permeable pads are neither rigid nor self-supporting. Hale""s apparatus may be ineffective if the infant""s nose and mouth are covered by the mattress and/or bedding so that air blown toward the infant has no effect on respiration.
A need has existed within the art for a sleeping pad that will provide passive ventilation of the crib without requiring pumps, fans or other such devices but be adapted to readily permit use of such supplemental air flow devices, if the user so chooses. In addition, it is desirable to provide a sleep pad that will sufficiently remove carbon dioxide and mucus or other fluid spit up by the child when sleeping thereby reducing the risks of SIDS and asphyxiation. Lastly, it is desirable to provide a sleeping pad, crib slat bumpers and gas and liquid transmissive bedding for use in a crib to enable: (a) expired respiratory gases to move away from the crib; (b) increase ventilation to the crib to reduce the risk of overheating and (c) supply sufficient oxygen to the crib to stimulate breathing.
It is therefore an object of the present invention to provide an apparatus for reducing the risks of Sudden Infant Death Syndrome and Asphyxiation, including the provision of a sleep pad for infants provided with passageways to enhance the availability of oxygen to the infant, including the face-down position, while at the same time passively removing carbon dioxide expired by the infant from the crib environment.
A still further object of the present invention is to provide a sleeping pad for an infant that is rigid enough to support the infant without the frame and support means required by prior art devices.
Yet another object of the invention is to provide a sleeping pad for an infant whereby the infant can comfortably rest on the pad without deformation of the passageways extending through the pad to thereby readily maintain transmission of respiratory gases therethrough.
Yet another object of the present invention is to provide a sleeping pad for infants having a grid-like configuration that will create a high surface area region for the transmission of respiratory gases.
Still a further object of the present invention is to provide a sleeping pad readily adapted to fit within a conventional crib and which can be used in conjunction with bumpers for the slats of a crib to provide safety against injury to the infant while also providing means to readily cause transmission to respiratory gases therethrough.
Another object of the present invention is to provide bumpers that prevent injury to the child in the event the child falls against the side walls of the crib.
Still a further object of the present invention is to provide crib slat bumpers that do not interfere with the transmission of respiratory gases through the crib environment.
Another object of the present invention is to provide a sleeping pad and bumper for a crib constructed from materials that allow respiratory gases to pass therethrough while maintaining rigidity to the pad and bumper.
Another object of the present invention is to provide a sleeping pad adapted to be selectively covered with a mesh or open-weave covering while retaining passive respiratory gas transmission properties.
Another object of the present invention is to provide a sleeping pad and bumper arrangement for a crib that readily transmits carbon dioxide gases expired from the infant therethrough thereby keeping the entire environment of the crib free from potentially toxic gases.
Still a further object of the present invention is to provide a blanket, comforter or bumpers each of which are adapted to provide passive transmission of respiratory gases into and out of the crib without the need for electrical devices, complex filter means, tubing, or other noise generating apparatus.
Another object is to provide a sleeping pad for an infant that will provide passive transmission of gaseous or liquid fluid material through the pad and away from the infant and is also adapted for use together with an exhaust fan or the like for enhancing the flow of gaseous or liquid fluid through the pad.
Still a further object of the present invention is to provide a mattress pad and bumpers for a crib that is readily adapted for use with different crib constructions.
It is another object of the present invention to reduce apnea and increase hypoxic arousal by decreasing hypoxia and hypercapnia (less than normal oxygen in organs and tissues) during the quiet sleep of infants.
There is yet a further object of the present invention to reduce risk of an infant overheating within a crib or play area thereby falling victim to Sudden Infant Death Syndrome.
Yet another object of the present invention is to decrease the rebreathing of expired carbon dioxide near the mouth and nose of an infant.
Still a further object of the present invention is to prevent the formation of pockets of carbon dioxide which may be trapped within bedding surrounding an infant.
Still a further object of the present invention is to safely increase the breathing efficiency of an infant experiencing inadequate shallow end tidal volume of the lungs.
Another object of the present invention is to reduce respiratory abnormalities in infants and the incidence of crib death by providing a flow of room air to the sleeping infants environment to stimulate breathing in a passive manner by means of infant bedding including pads, bumpers, comforters, blankets and fitted sheets.
These and other objects of the present invention are achieved by providing a sleeping pad for an infant that is adapted to readily promote ventilation therethrough during use comprising a support member having a top, a bottom and sides, the support member adapted to resiliently support an infant thereon, a plurality of substantially planar, four sided passageways extending through the support member from the top to the bottom, each one of these sides is perpendicular to the top and the bottom and abuts against an adjacent one of the sides from the top to the bottom to readily transmit fluid therethrough and at least the sides are formed from a material having low compressibility whereby when an infant is supported on the pad, the passageways maintain their shape throughout and readily transmit gaseous and liquid fluid therethrough and an exhaust fan operatively associated with the sleeping pad for enhancing the flow of gaseous material through the passageways.
The present invention is also directed to an infant""s crib adapted to readily promote ventilation therethrough comprising in combination a crib frame having a bottom and side railings including slats, a sleeping pad positioned on a crib from bottom, the pad comprising a support member having a top, a bottom and sides, the support member adapted to resiliently support an infant thereon, a plurality of substantially planar, four sided passageways extending through the support member from the top to the bottom, each one of the passageway sides extends perpendicular to the top and the bottom and abuts against an adjacent one of the passageways sides from the top to the bottom to readily transmit fluid therethrough and at least the passageway sides for formed from a material having sufficiently low compressibility whereby when an infant is supported on the cushion, the passageways substantially maintain their shape throughout and thereby readily transmit gaseous and liquid fluid therethrough, an exhaust fan operatively associated with the sleeping pad for enhancing the flow of gaseous material through the passageways and a slat cushion, the slat cushion having a top, a bottom, a first side and a second side, the slat cushion is adapted to allow transmission of respiratory gases therethrough and is affixed against at least one of the crib slats to provide a cushion thereagainst.
The present invention is further directed to bedding (comforter, blanket) adapted to readily promote passive ventilation therethrough comprising a cover adapted to readily enable gas and fluid to pass therethrough and gas transmissive fill material enclosed within said cover.
The present invention is also directed to a cushion for the slats of a crib, the cushion comprising a top, a bottom, a first side and a second side, means for securing the cushion to at least one slat of a crib wherein the cushion is adapted to allow transmission of respiratory gases therethrough.
These and other objects and advantages of the present invention will become apparent from the following description of the preferred embodiment taken together with the accompanying drawings.